Extensible rule



A ril 3, 1956 c. J. SWANSON 2,740,201

EXTENSIBLE RULE Filed Aug. 16, 1954 3 Sheets-Sheet l INVENTOR. CARL J. SWANSON APIril 3, 1956 c. J. SWANSON 2,740,201

EXTENSIBLE RULE Filed Aug. 16, 1954 3 Sheets-Sheet 3 CARL. J- SWANSON United States Patent EXTENSIELE RULE Carl J. Swanson, New York, N. Y. Application August 16, 1954, Serial No. 449,909 Claims. (Cl. 33161) This invention relates to an extensible rule, and more particularly has reference to a rule of the type shown in my previous United States Patent No. 2,356,544, dated August 22, 1944. The invention is also an improvement over the rules shown in my United States Patents, Nos. 2,270,227, dated January 13, 1942, and 2,270,335, dated January 20, 1942.

An important object of the present invention is to provide a rule having telescopically related, channel shaped extensible sections, which sections will be particularly designed to reduce to a minimum the amount of surface area of each section that is in contact, during extension or retraction of the rule, with adjacent sections. To this end, the several sections are each formed with recessed areas, facing interiorly of the sections, which areas are out of contact with the adjacent surfaces of adjacent sections.

Another object of importance is to provide, in a rule of the type referred to, inwardly turned longitudinal flanges on the side walls of the respective sections, said flanges being disposed in nested relation on telescoping of the rule sections, the flanges being adapted to strengthen the rule from end to end thereof.

Another object is to provide shallow, dovetail recesses extending longitudinally of the respective sections, which recesses will be adapted to receive insert strips of plastic or the like, having graduations appearing thereon, thus to eliminate the marking of the graduations on the surfaces of the metal sections.

Other objects are to provide a rule of the type stated that will be capable of manufacture at relatively low cost; will have the undercut flanks of certain of the recesses of the sections rounded off to eliminate sharp edges; and will include a novelly designed locking plate constituting an improvement over the corresponding plate in my Patent No. 2,356,544.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Figs. 1 and 1A are back views of the rule, the rule being almost fully collapsed.

Figs. 2 and 2A are face views.

Fig. 3 is an enlarged transverse sectional view on line 3-3 of Fig. 1.

Fig. 4 is a greatly enlarged, fragmentary cross sectional view of the web part of the outermost sections.

Fig. 5 is a fragmentary cross sectional view on the same scale as Fig. 4, of the flanged side walls of the outermost rule section.

Fig. 6 is a perspective view of the locking plate, per se.

Fig. 7 is an exploded perspective view of the detent means.

Fig. 8 is an enlarged longitudinal sectional view on line 88 of Fig. 1A, showing the means for reproducing measurements.

Fig. 9 is an enlarged transverse sectional view on line 99 of Fig. 8.

Fig. 10 is a view showing the device in use.

Fig. 11 is a sectional view on line 11-1l of Fig. 1A.

Fig. 12 is a sectional view on line 12-12 of Fig. 11.

The rule 10 constituting the present invention includes a plurality of telescoping, nestable sections 12, 14, 16, 18, 20, 22 and 24. Each section is of channel cross sectional shape, having side walls disposed at right angles to its web.

The several sections have recessed surfaces. Thus, the outer section 12, as best shown in Figs. 3-5, includes a shallow longitudinal recess 26 extending the full length of the outer surface of the web part thereof. Recess 26, as shown in Fig. 4, is of dovetail cross section, having undercut flanks 28. The flanks 28 are of compound curvature when seen in cross section, the rounding off of the flanks being designed to eliminate blade-like edges or crevices in which dirt can lodge.

Each of the other sections, as shown in Fig. 3, also has a longitudinal recess disposed on the outer surface of the web part thereof.

Engaged in the several dovetail longitudinal recesses of the sections are insert strips 27, the outer surfaces of which are marked with suitable graduations, in a manner to be made apparent hereinafter. The strips are of Celluloid or other plastic material, and the use thereof eliminates the necessity for marking the graduations directly upon the surface of the metal. Each strip is of a cross-sectional configuration complementing that of its associated recess.

The outermost section 12 also has, on these edges of its side walls remote from the web part, confronting, in wardly extending, coplanar longitudinal flanges 30. These serve to reinforce the device, and for formed with recesses 32 of angular cross section along their free, inwardly turned edges.

The flanks of the recesses 32 can, as shown in Fig. 5, be rounded olf as at 34, in the same manner as the flanks of recess 26. A longitudinal closure strip 35 of Celluloid or other plastic material, is engaged in recesses 32 to prevent dirt from entering the rule.

The several sections 1424 are also formed with inwardly turned, confronting longitudinal flanges, the several flanges being nested with the free edge of each flange of said sections 14-24 being offset outwardly from the corresponding edge of the next adjacent flange, in a direction outwardly from the innermost section. This is particularly shown to advantage in Fig. 3.

Also as shown in Fig. 3, the inner surface of each side wall of the outermost section 12 is formed with longitudinal recesses 33, 35. These extend the full length of section 12, and are of shallow formation. Recess 33 is closer to the web part of the outermost section and is approximately three times the width of the recess 35.

Similar recesses are formed in the inner surfaces of the side walls of sections 14-22, to reduce to a minimum the amount of surface area in contact between the side walls of the several sections.

By reason of the arrangement illustrated, when the rule is being extended or retracted, the sections offer a minimum amount of frictional resistance to the relative slidable movement thereof, thus making quite easy the task of extending the rule or retracting it after use. Further, due to the provision of the several nestable reinforcing flanges, the rule is strongly reinforced against undesirable flexure when fully extended.

A quick-release lock means is provided to lock the several sections against relative movement.

As shown in Fig. 3 and also in Fig. 6, the lock means includes a smooth-surfaced shank or stem 38 extending transversely of a yoke 36 of inverted U-shape, the sides or-lcgs of the yoke being fixedlysecured to the outer surfaces of the side walls of the section 12. The legs of said yoke are provided with transversely aligned, smooth-walled openings, receiving the ends of the stem 38. A knob 46 is rigidly secured to one end of the stem.

Depending from the intermediate portion of the stem 38 is a locking bar 41 shaped as shown in Fig. 6. Bar 41 has a smooth-walled opening 41 receiving stem 38, a cross pin 42 being inserted through a diametrically extending aperture formed in the stem to engage against one side of the locking bar and thereby limit movement of the locking bar in one direction upon the stem. The top surface of the locking bar is flat, and is in engagement with the underside of the night of the yoke 36, to prevent rotation of the locking bar upon the stem.

A spring 43 is interposed between the locking bar 41 and one leg of the yoke 36, and is held under compression so as to continuously urge the locking bar against the cross pin 42.

The depending, free end portion of the locking bar 41 is formed with a recess 44 shaped to clear the several inwardly extending flanges of the sections. Recess 44 terminates adjacent the lower end surface of the locking bar, so as to define a nose 45 upon the locking bar that engages against the inner surface of one side wall of the innermost section.

On that end of the stem remote from the knob 40 there is secured to the stem 38 a collar 46 which, in the locking position of the parts shown in full lines in Fig. 3, is spaced away from the adjacent leg of the yoke 36.

A lock plate 47 is mounted upon the opposite leg of the yoke, and interposed between said opposite leg and the plate 47 is a spring 48 comprising a pair of spring coils so tensioned as to normally bias the lock plate 47 to the inclined or tilted position shown in full lines in Fig. 3.

At its lower end, the locking plate is rockably mounted upon the leg of the yoke, said leg of the yoke having a slot 53 in which is loosely engaged a tongue 51 ofiset inwardly from and formed integrally with the lower end portion of the lock plate 47.

Lock plate 47 has intermediate its ends an opening 49 of a diameter somewhat greater than that of the stem 38. The upper edge portion of the opening 49 engages against the stem 38 in each position to which the stem is shifted in an axial direction.

In use of the lock means, the user, whenever he desires to lock the several sections against relative longitudinal movement, presses inwardly upon the knob 49, thus to shift the parts to the full line position of Fig. 3. Spring 43 is placed under compression, but cannot return the parts to their original position shown in dotted lines in Fig. 3, because the lock plate 47, shifted to its tilted position by its spring 48, bites into the surface of the stem 38, to hold the stem in its inwardly shifted or locking position.

As a result, the nose 4S presses against the adjacent side wall of the innermost section, and the pressure is transmitted to the several sections, sov as to bind the sections frictionally against relative longitudinal movement.

-When it is desired to unlock the sections, to permit relative longitudinal movement, the quick release lock means is disengaged merely by exerting a slight pressure on the upper end portion of the lock plate 47, tending to shift the lock plate to the dotted line position shown in Fig. 3. move out of biting engagement with the stem 38, and spring 43, now free to expand, shifts the stem and hence the locking bar 41, to the dotted line position shown in Fig. 3. The collar 46, engaging against the adjacent leg of the yoke 36, causes the locking bar to move no further This causes the edge of the opening 49 to than the middle of the space between the side walls of the innermost section.

The locking plate 47, of course, will at all times permit movement of the stem 38 from the dotted to the full line positions shown in Fig. 3, and will not bite against the stem until the stem has been shifted to its full locking position, and the knob has been released.

In Fig. 7 and also in Fig. 3 there is shown a means for locking the sections when extended. This is as shown in my Patent No. 2,356,544 and does not per se constitute part of the present invention. However, the means has been shown in detail, to provide a full understanding of the improved construction.

The last-named locking means includes a tube 50 fixedly secured to a fiat locking plate 52, that is attached by screws 54 to the web of each section other than the outermost section 12, said plate 52 being secured to its associated section at the inner end of the section. Tube 59 is of noncircular cross section, and intermediate opposite ends of tube 50 there is provided a compression spring 56, that is held under compression between locking lugs 58. Lugs 58 are fioatingly mounted in the respec tive ends of tube 50, to slide outwardly and inwardly of the tube. Each lug 58, at its outer end, has a reduced part 60, terminating in a cam surface 62. Part 60 extends, when the sections are extended, into complementary slots provided in the respective sections, to releasably lock the sections in extended position.

As shown in Figs. 8 and 9, the improved rule includesa means for hooking-the rule onto an object from which measurement is to be taken. This means, which is basically similar to that shown in Patent No. 2,356,544, includes longitudinally spaced blocks 64, 66 fixedly secured by screws 68 to the innermost section 24, and having aligned openings in which is slidable a stem 70 provided at one end with a hook-like handle 72. The opening of block 66 is noncircular, and the inner end portion of the stem is noncircularly formed, to prevent rotation of the stem. A spring 74 is held under compression between block 64 and a cross pin 75 carried. by the stem, the pin 75 engaging the block 66 in the expanded condition of spring 74. Beyond the block 66, the stem has a collar 76.

The handle 72, when the spring is fully expanded, engages in a notch or recess 78 provided in the outer end of the section 24. Further, as shown in Fig. 2A,. when the section 24 is telescoped into the adjacent section 12 in the fullycollapsed position of the rule, the hook element 72 engages in a notch 79 provided in the outer end of thesection 12.

The faces of the several strips 27 are marked off. with suitable indicia. Indicia 80 are provided, marking off;

the sections in inches, and indicia 82 mark the sections off in feet. The reading is taken at theouter end of section 12, said outer end of section 12 constitutinganv index registrable with selected indicia when the rule;

is extended to take a measurement. 7 It is to be understood that the various parts of this device may be made of any suitable material, such as plastics, metal, etc.

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. An extensible rule comprising a series of channelshaped sections, each section except the outermost section being frictionally slid-able within another in nested telescoping relationship, each section having a flat web.

and side walls lying in planes normal to that of theweb,

at least some of the sections having shallow recessesexa:

tending the length of the outer surfaces of the webs, graduated strips engaged in the recesses, some at least of the sections additionally having recessed formed in the inner surfaces of the side walls thereof, to reduce the amount of surface area of the side walls in contact with adjacent side walls, each side wall having a plurality of recesses therein, the recesses of each side wall differing in width from one another, opposed flanges on the outermost section, said flanges having recesses with rounded, undercut flanks, and a closure strip in said latter recesses.

2. An extensible rule comprising a series of channelshaped sections, each section except the outermost sec tion being frictionally slidable within another in nested telescoping relationship, each section having a flat web and side walls lying in planes normal to that of the web, at least some of the sections having shallow recesses extending the length of the outer surfaces of the webs, and graduated strips engaged in the recesses, some at least of the sections additionally having recesses formed in the inner surfaces of the side walls thereof, to reduce the amount of surface area of the side walls in contact with adjacent side walls, each side wall having a plurality of recesses therein, the recesses of each side Wall differing in width from one another, some at least of the recesses of the web having rounded, undercut flanks.

3. An extensible rule comprising a series of channelshaped sections, each section except the outermost section being frictionally slidable within another in nested telescoping relationship, each section having a flat web and side walls lying in planes normal to that of the web, and longitudinal flanges formed upon the side walls of each section, the flanges of each section being disposed in coplanar relationshi the flanges of each section being in contact with the corresponding flanges of the next adja-cent section, on nesting of the sections in telescoping relationship, the flanges of each section having confronting inner longitudinal edges offset transversely of the sections from the corresponding edges of the flanges of the remaining sections, said rule further including a lock bar extending into the innermost of the telescoping sections, means for shifting the lock bar transversely of the sections into engagement with the side wall of said innermost section, whereby to force said side wall against the adjacent side walls of the remaining sections to lock the sections frictionally in their telescoped relationship, said means comprising a stem mounted on one of the sections for movement transversely thereof and carrying the lock bar with it during said movement, spring means arranged to bias the stem in a direction to shift the lock bar out of engagement with the side Wall of said innermost section, and a quickly releasable locking element associated with the stem and adapted to releasably engage the stem against movement by the spring in said direction.

4. An extensible rule comprising a series of channelshaped sections, each section except the outermost section being frictionally slidable Within another in nested telescoping relationship, each section having a flat web and side walls lying in planes normal to that of the web, and longitudinal flanges formed upon the side walls of each section, the flanges of each section being disposed in coplanar relationship, the flanges of each section being in contact with the corresponding flanges of the next adjacent section, on nesting of the sections in telescoping relationship, the flanges of each section having confronting inner longitudinal edges offset transversely of the sections from the corresponding edges of the flanges of the remaining sections, said rule further including a lock bar extending into the innermost of the telescoping sections,

means for shifting the lock bar transversely of the sections into engagement with the side wall of said innermost section, whereby to force said side wall against the adjacent side walls of the remaining sections to lock the sections frictionally in their telescoped relationship, said means comprising a stem mounted on one of the sections for movement transversely thereof and carrying the lock bar with it during said movement, spring means arranged to bias the stem in a direction to shift the lock bar out of engagement with the side wall of said innermost section, a quickly releasable locking element associated with the stem and adapted to releasably engage the stem against movement by the spring in said direction, said quickly releasable locking element comprising a plate having an opening in which the stem is slidable, the plate being tiltably mounted upon said one section with the edge of the opening of the plate adapted to bite into the stem on tilting of the plate, and spring means tending to bias said plate into its tilted, stem-engaging position.

5. An extensible rule comprising a series of channelshaped sections, each section except the outermost section being frictionally slidable within another in nested telescoping relationship, each section having a flat Web and side Walls lying in planes normal to that of the web, and longitudinal flanges formed upon the side walls of each section, the flanges of each section being disposed in co-planar relationship, the flanges of each section being in contact with the corresponding flanges of the next adjacent section, on nesting of the sections in telescoping relationship, the flanges of each section having confronting inner longitudinal edges offset transversely of the sections from the corresponding edges of the flanges of the remaining sections, said rule further including a lock bar extending into the innermost of the telescoping section, means for shifting the lock bar transversely of the sections into engagement With the side Wall of said innermost section, whereby to force said side wall against the adjacent sidewalls of the remaining sections to lock the sections frictionally in their telescoped relationship, said means comprising a stem mounted on one of the sections for movement transversely thereof and carrying the lock bar with it during said movement, spring means arranged to bias the stem in a direction to shift the lock bar out of engagement with the side wall of said innermost section, a quickly releasable locking element associated with the stem and adapted to releasably engage the stem against movement by the spring in said direction, said quickly releasable locking element comprising a plate having an opening in which the stem is slidable, the plate being .tiltably mounted upon said one section with the edge of the opening of the plate adapted to bite into the stem on tilting of the plate, and spring means tending to bias said plate into its tilted, stem-engaging position, said plate lying in a plane oblique to the axis of the stem when in its stem-engaging position, the plate being arranged to be shifted manually into a plane normal to the stem axis, the edge of the opening of the plate being out of engagement with the stem in said last-named plane.

References Cited in the file of this patent UNITED STATES PATENTS 907,612 Krehlik Dec. 22, 1908 1,014,547 Willis Jan. 9, 1912 1,050,733 Greathead Jan. 14, 1913 1,528,992 Rose Mar. 10, 1925 1,629,829 Linn May 24, 1927 2,356,544 Swanson Aug. 22, 1944 

